Magnetic cuff link



, P 7, 949. H. AVEDON 2,483,031

MAGNETIC CUFF LINK Filed June 4, 1948 IN VEN TOR.

Harvey JII/edon BY M v rm ATTOQNEYS Patented Sept. 27, 1949 UNITED STATES PATENT OFFICE MAGNETIC CUFF LINK Harvey Avedon, New York, N. Y.

Application June 4, 1948, Serial No. 31,087

1 Claim.

My invention relates primarily to a new and improved cull-link, whose parts or halves are held releasably to each other by magnetic force. The invention applies to other purposes.

One embodiment of the invention is explained in the annexed description and drawings.

Fig. 1 is an elevation of one part of the cuff-link with a part broken away to show it in vertical section;

Fig. 2 is an elevation of the other part of the cuff-link, partially in vertical section;

Fig. 3 is a top plan view on the line 33 of Fig. 2, part of the representation of the top pole plate being broken away; and

Fig. 4 is an elevation of the assembled cuff-link.

The first part or half I4 of the cull-link, shown in Fig. 1. comprises an end-plate I and an armature A. The armature A is made of soft iron. Plate I and armature A are connected by eyes 2 and 2a and a link 8, so that there is some relative movement between the connected plate I and armature A. This is designated as a flexible connection. Armature A has an inner part 5 and an enlarged head 5a. Plate I. and armature A may be of circular outline. As shown in Fig. 1, the armature A is recessed at head 5a.

The second part or half Ha of the cuff-link, shown in Fig. 2, comprises a pole cup 6, made of soft iron, which is connected to end-plate I2 by eyes It and Illa and link I I, to provide some relative movement. A magnet 8 is located in pole cup 8. Magnet 8 is held in position relative to the 2 8 is "south and that outer face 8a of magnet 8 is north, the magnetic flux will extend from north face 8a to the permeable pole plate 'I, then across the very narrow gap between pole plate 'I and wall 6a, which in effect is an air gap, and then through I soft iron pole cup 6, wholly by magnetic force.

The soft iron pole plate I is held to magnet 8 by magnetic force. As above noted the annular lateral space between magnet 8 and wall or flange cylindrical flange 8a of pole-cup 6 by spacer cup 8,

made of brass or other suitable material, which is substantially non-permeable to the magnetic flux.

An air gap G is thus provided between the flange 8a of the soft iron pole cup 6 and the soft iron pole plate 'I.

The outer and inner faces 8a and 8b of magnet 8 are of respective opposite magnetic polarities.

As sho' n in Fig. 2, the spacer cup 9 has a longitudinal cylindrical part or flange which is located between the longitudinal cylindrical wall 6a of cup 6, and the longitudinal cylindrical edge-wall of pole plate I. Due to the low permeability of the material of spacer cup I, the effect is the same as though a narrow, annular air-gap were provided between wail 6a and the edge wall of pole plate I.

As also shown in Fig. 2, there is a much wider air gap between the longitudinal and cylindrical edge-wall of magnet 8 and longitudinal wall 6a of'cup 8. Hence, the magnetic flux will not be short-circuited between magnet 8 and wall 80.

Thus, assuming that the inner face 8b of magnet 6a. is of much greater width than air-gap G. As previously noted, said lateral annular space is in effect an air-gap, due to the low permeability of spacer cup 9, so that the magnetic flux is concentrated across air-gap G, when parts It and Ila are separated.

When the soft iron armature A is contacted with the soft iron pole plate I, as shown in Fig. 4, the magnetic flux passes through said soft iron armature A, so that little or no magnetic flux passes through air-gap G.

The two parts II and Ila will thus be flrmly L and releasably connected.

When the parts are assembled as shown in Fig. 4, the inner planar annular wall of armature A makes full contact with the planar edge-wall of longitudinal wall 6a and also with the planar outer wall of pole plate I. Substantially all the flux will then pass directly from the longitudinal wall 6a to armature A, and back to the pole plate I, directly adjacent the gap between wall 6a and pole plate I. This effect is aided by the recesses construction at the inner face of armature A. This produces a very short path for the magnetic flux between pole cup 6 and armature A, so that a small permanent magnet 8 will exert the desired coupling or holding force. An important feature is to provide a recess between the armature A and pole plate I, when the parts are assembled, so that the magnetic flux extends in generally longitudinal back-and-forth path, close to the gap between wall in and pole plate I.

The drawings are substantially to a scale of four to one, and reference is made thereto for further disclosure.

When I refer to the use of soft iron, I include material which has little or no permanent or residual magnetism, and which is highly permeable to the magnetic flux.

The flexible eye and link connection aids in preventing accidental separation between the parts l4 and Ma.

The exposed planar face of-pole plate I is flush or substantially flush with the planar annular edge-face of flange in, so that the planar end face of head 5a abuts the edge-face of fiange 6a and the exposed face of pole plate I, when parts Hi and Ma are assembled.

The end-plates I, I2 and the eyes and links may be made of gold, silver or other material which is preferably not paramagnetic or diamagnetic.

I have disclosed a preferred embodiment of my invention, but numerous changes and omissions can be made without departing from its scope.

I claim:

A cuiT-link which comprises a first part and a second part which are adapted to be assembled in longitudinal relation, each part having an endplate, an armature connected to the end-plate of the first part, said armature being made of material which is permeable to magnetic fiux and which has little residual magnetism, the end plate of said second part being connected to a pole cup of said material, said pole cup having a lateral base and a longitudinal wall, a permanent magnet located in said pole cup and abutting the inner face of said lateral base, said permanent magnet having a longitudinal wall which is separated by a lateral space from the inner face of the longitudinal wall of said cup, a pole plate which abuts the outer face of said permanent magnet. said pole plate having an outer face which is aligned with the end-wall oi the longitudinal wall of said cup, said pole plate being made of said material and being separated from the inner face of the longitudinal wall'ot said cup by an air gap which is or much less width than said lateral space so that substantially all the magnetic flux passes through said air-gap when said parts of the cuiI-link are separated, said armature having an end-wall which abuts the end-wall of said longitudinal wall and which abuts the outer face of said pole plate to bridge said air-gap when said parts of the cull-link are assembled, said assembled armature and pole plate being located between said end plates when said parts of the cuff-link are assembled, said assembled armature and pole plate having a lateral air space whose outer edge is close to said air-gap, so that when said parts of the cull-link are assembled, the fiux enters said armature and leaves said armature close to said air gap and there is then substantially zero fiux through said air gap.

HARVEY AVEDON.

REFERENCES CITED The following references are oi record in the file of this patent:

UNITED STATES PATENTS 

